Rewrite ${\dfrac{9^{-6}}{9^{-12}}}$ in the form ${9^n}$.
Answer: ${ \dfrac{9^{-6}}{9^{-12}} = 9^{-6-(-12)}} $ ${ \hphantom{\dfrac{9^{-6}}{9^{-12}}} = 9^{6}} $